Closed loop vacuum cleaner

ABSTRACT

A vacuum cleaner which includes a closed loop air system is disclosed. The closed loop air system has an entering chamber, a fan in communication with the chamber, an electrical motor which drives the fan, a filtering unit connected to the entering chamber via a hose, an air jet nozzle located adjacent the chamber, and a hose connecting the nozzle to the filtering unit. Air laden with dirt and debris is picked up from the surface being cleaned and is sucked into the chamber via the fan. The air is directed to the filtering unit where it removes the dirt and debris. The cleaned air is returned to the nozzle. The air stream is again polluted by dirt and dust and is immediately sucked into the cleaner by the fan into the entering chamber. In a further embodiment, an additional fan or blower is employed to increase the air pressure at the nozzle.

BACKGROUND OF THE INVENTION

[0001] The present invention is directed toward a vacuum cleaner and more particularly, toward a vacuum cleaner with a closed loop air system.

[0002] A conventional vacuum cleaner includes an entering chamber or nozzle, a fan which is usually driven by an electrical motor, and a filtering unit connected to the entering chamber via pipes or hoses. The entering chamber is placed in the vicinity of the surface being cleaned. The ambient air along with dirt and debris from the surface is sucked into the machine by the fan and through the entering chamber. The air, now polluted with the dirt and debris, is directed by the fan into the filtering unit which retains the dirt but releases the clean air back into the surrounding air.

[0003] Porous filters such as reusable cloth bags or disposable paper bags are often used as part of the filtering unit and are used to capture the dirt and debris collected by the cleaner yet allow the clean air to return to the surrounding air. A problem with these filters, however, is that inevitably fine dust will escape along with the clean air and will be released back into the surrounding air.

[0004] An alternative to using bag filters is to use cyclones or scrubbers such as shown, for example, in U.S. Pat. No. 4,853,008 to Dyson and U.S. Pat. No. 6,200,361 issued to one of the present Applicants. While these filters are an improvement over more conventional filters, very fine dust may still escape with the filtered clean air.

[0005] Typically, upright vacuum cleaners contain a rotating brush which is located adjacent or within the entering chamber of the vacuum cleaner and is used to loosen or otherwise kick up dust and dirt embedded in the surface being cleaned so that the dirt is swept into the path of the air flowing into the entering chamber. See, for example, U.S. Pat. No. 4,219,902 to DeMaagd and U.S. Pat. No. 4,446,594 to Watanabe et al. Vacuum cleaners using rotary brushes, however, are not very efficient in that the use of a rotating brush makes the cleaner heavy and may involve the use of a complicated and/or heavy motor. Also, the use of a rotating brush requires additional consumption of energy.

[0006] Therefore, in light of all of the inefficiencies present with typical vacuum cleaners, a need exists for an improved vacuum cleaner which does not allow dust and dirt that had been collected from a surface to be returned to the air as the surface is being cleaned.

SUMMARY OF THE INVENTION

[0007] The present invention is designed to overcome the deficiencies of the prior art discussed above. It is an object of the present invention to provide a vacuum cleaner which provides a more efficient way to clean a surface.

[0008] It is a further object of the present invention to provide a vacuum cleaner with a closed loop air system which prevents dirt and debris from returning to the ambient air once it has been collected.

[0009] In accordance with the illustrative embodiments demonstrating features and advantages of the present invention, there is provided a vacuum cleaner with a closed loop air system which includes an entering chamber, a fan in communication with the chamber, an electrical motor which drives the fan, a filtering unit connected to the entering chamber via a hose, and means for returning air from the filtering unit to the entering chamber. The air returning means includes a hose and an air jet nozzle. The hose connects the output of the filtering unit to the air jet nozzle which is located adjacent the entering chamber. Air laden with dirt and debris is picked up from the surface being cleaned and is sucked into the chamber via the fan. The air is directed to the filtering unit where the filtering unit retains the dirt and debris. The cleaned air is returned to the nozzle. The air stream is again polluted by dirt and dust and is immediately sucked into the cleaner by the fan into the entering chamber. In this manner, the cleaner uses a constant motion of air without releasing it to the environment. In a further embodiment, the single fan is replaced with two smaller fans.

[0010] Other objects, features, and advantages of the invention will be readily apparent from the following detailed description of the embodiments thereof taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] For the purpose of illustrating the invention, there is shown in the accompanying drawings forms which are presently preferred it being understood that the invention is not intended to be limited to the precise arrangements and instrumentalities shown.

[0012]FIG. 1 is a side elevational diagrammatic view of a first embodiment of the present invention, and

[0013]FIG. 2 is a side elevational diagrammatic view of a second embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Referring now to the drawings in detail wherein similar reference numerals have been used in the two figures to designate similar elements, there is shown in FIG. 1 a vacuum cleaner constructed in accordance with the principles of the present invention and designated generally as 10.

[0015]FIG. 1 illustrates a first embodiment of the present invention incorporated into an upright vacuum cleaner. As should be readily apparent to those skilled in the art, the vacuum cleaner of FIG. 1 is shown diagrammatically. That is, many of the features thereof are conventional and the details are, therefore, not believed necessary for a full understanding of the invention.

[0016] The vacuum cleaner 10 of the present invention essentially includes a closed loop air system which includes an entering chamber 12, a fan 14 in communication with the chamber 12, an electric motor 16 which drives the fan 14, a filtering unit 18 connected to the entering chamber 12 via a hose 20, and means for returning air from the filtering unit 18 to the area in front of the entering chamber 12. The air returning means includes a line or a hose 22 and an air jet nozzle 24. The hose 22 connects the filtering unit 18 to the air jet nozzle 24. The air jet nozzle 24 is preferably in the form of an elongated narrow slit located adjacent the front of the entering chamber 12 and is arranged to direct air at high pressure toward the surface 28 being cleaned.

[0017] In operation, the motor 16 is activated so that air laden with dirt and debris from the surface 28 enters the cleaner through the chamber 12. The polluted air is sucked into the chamber 12 via fan 14. The air is directed to the filtering unit 18 through hose 20. The filtering unit 18 retains the dirt and debris. All of the cleaned air from the filtering unit 18 then enters the hose 22 which returns the air to the nozzle 24. The thrust of the air stream agitates the surface being cleaned, thereby loosening the dirt and debris therein so that the dirt and debris may be sucked into the cleaner. The air stream, again polluted by dirt and dust, is immediately sucked into the cleaner by the fan 14 into the entering chamber 12. In this manner, the cleaner uses a constant motion of recycled air without releasing it to the environment.

[0018] A second embodiment of the present invention is shown in FIG. 2. This embodiment is similar in structure to the first embodiment with the differences discussed below. Accordingly, elements of FIG. 2 that are essentially the same as those of FIG. 1 are numbered the same as in FIG. 1 but are preceded with the number 1.

[0019] The vacuum cleaner system of FIG. 2 is, thus, designated generally as 110. The closed loop air system includes an entering chamber 112, fan 114 in communication with the chamber 112, an electrical motor 116 which drives the fan 114, a filtering unit 118 connected to the entering chamber 112 via a hose 120, and means for returning air from the filtering unit 118 toward the entering chamber 112. The air returning means includes a hose 122 and an air jet nozzle 124 located adjacent the front of the entering chamber 112.

[0020] As with the first embodiment of the invention, the nozzle 124 is directed toward the surface 128 being cleaned. To aid in the cleaning effect, however, this embodiment includes an additional fan or blower 115 in the air line between the air return hose 122 and the nozzle 124. Fan 115 is preferably also driven by motor 116. The additional fan 115 increases the pressure of the air leaving the nozzle 124 which increases its ability to agitate and loosen dirt from the surface 128 being cleaned.

[0021] In operation, the motor 116 is activated so that air laden with dirt and debris from the surface 128 enters the cleaner through the chamber 112. The polluted air is sucked into the chamber 112 via fan 114. The air is directed to the filtering unit 118 through hose 120. The filtering unit retains the dirt and debris and all of the cleaned air enters the hose 122 to be returned to the nozzle 124. The air pressure is increased by the blower 115 and the thrust of the air stream exiting nozzle 124 agitates the surface 128 being cleaned, thereby loosening the dirt and debris therein so that the dirt and debris may be sucked into the cleaner. The air stream, again polluted by dirt and dust, is immediately sucked into the entering chamber 112 by fan 114. As in the first embodiment, the cleaner in this embodiment uses a constant motion of recycling air without releasing collected pollutants back into the environment.

[0022] In both embodiments, the filtering unit 118 may be any of those known in the art, such as a cloth or disposable bag or, preferably, as shown in the Figures, a scrubber, or a cyclone as described in the above mentioned patents. In addition, although the invention is shown using a single slit nozzle, it may also be possible to utilize a plurality of smaller air jet nozzles arranged in a row or some other predetermined pattern.

[0023] If low pressure drop filtering units, such as cyclones or scrubbers, are used the air stream thrust can replace conventionally used rotating brushes typically placed within or adjacent the entering chamber. The removal of the brush in the present invention makes the vacuum cleaner simple and lighter because it contains less moving parts. This cleaner also requires less energy because a smaller, lighter motor may be used. Furthermore, the air thrust has better cleaning ability than mechanical brushes because the air is able to penetrate smaller and obscure areas. Thus, the present system allows for a more efficient way to clean a surface.

[0024] The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and accordingly, references should be made to the appended claims rather than to the foregoing specification as indicating the scope of the invention. 

We claim:
 1. A closed loop vacuum cleaner comprising: an entering chamber through which air laden with dirt or pollutants enters; at least one fan in communication with said chamber; an electrical motor driving said fan; means for filtering the dirt and pollutants from the air, said filtering means being connected to said entering chamber; and means for returning the filtered air from said filtering means to an area of said vacuum adjacent said chamber.
 2. The closed loop vacuum cleaner of claim 1 wherein said filtering means includes a scrubber filter.
 3. The closed loop vacuum cleaner of claim 1 wherein said air returning system includes an air jet nozzle and a hose which connects said filtering means to said air jet nozzle.
 4. The closed loop vacuum cleaner of claim 3 wherein said air jet nozzle directs air under pressure to the surface to be cleaned by said vacuum cleaner.
 5. The closed loop vacuum cleaner of claim 3 further including a fan located ahead of said air jet nozzle for increasing the pressure of the air being delivered to said nozzle. 